A standardization organization such as 3GPP (Third Generation Partnership Project) has promoting standardization of a small base station that can be installed in a user's house, an office or the like. This small base station is arranged in a house, a small office or the like by a user, and is connected to a core network via an access line which is a fixed line including an ADSL (Asymmetric Digital Subscriber Line), an optical fiber line or the like. Such a small base station is generally called a femto base station, a femtocell base station, or a home base station. Further, the size (coverage area) of a cell formed by the small base station is extremely small compared to those of macrocells. Thus, the cell formed by the small base station is called a femtocell or a home cell, for example. The 3GPP defines such a small base station as a Home Node B (HNB) and a Home evolved Node B (HeNB) and has promoting standardization work. The HNB is a small base station for UTRAN (Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network), and the HeNB is a small base station for LTE (Long term evolution)/E-UTRAN (Evolved UTRAN).
In this specification, the small base station as stated above is referred to as a “home base station”, and a cell formed by the home base station is referred to as a “home cell”. The home base stations for UTRAN and E-UTRAN studied by 3GPP are referred to as an HNB or an HeNB, or collectively referred to as an H(e)NB according to the name called in 3GPP. Further, the home cell formed by the H(e)NB is referred to as an “H(e)NB cell”.
In 3GPP Release 8, the H(e)NB is standardized as the base station managed by the user (see non-patent literature 1). However, it is difficult for the user to appropriately set configurations of the H(e)NB and H(e)NB cell (e.g. a radio frequency, a scrambling code/a physical cell ID, downlink transmission power). Accordingly, it is concerned that inappropriate configuration of the H(e)NB cell causes a problem of an interference between the M(e)NB cell and the H(e)NB cell. The M(e)NB cell is a macrocell generated by the M(e)NB (macro NodeB or macro eNodeB).
In order to suppress the interference between the H(e)NB cell and the M(e)NB cell, it has been considered that the H(e)NB shall have a function for autonomously setting radio parameters (referred to as self configuration, automatic configuration or the like). The radio parameters specify the characteristics of the radio communication, and more specifically, include a radio frequency band, a scrambling code, transmission power of a pilot signal (CPICH: Common Pilot Channel), and a maximum value of uplink transmission power by a mobile station, for example. Further, in order to achieve autonomous self configuration, it has also been considered that the H(e)NB shall have a function of receiving a downlink signal from a nearby macrocell (referred to as Network Listen Mode, Radio Environment Measurement or the like).
Another method that is proposed to suppress interference between the M(e)NB cell and the H(e)NB cell is to transmit configuration information of the H(e)NB cell to the H(e)NB from a control apparatus such as an RNC (Radio Network Controller) managed by a network operator (see non-patent literature 2). The H(e)NB performs setting regarding the H(e)NB cell based on the received configuration information. This method is supposed to be used together with the self configuration stated above. Since the self configuration is supposed to be performed at the time of set-up of the H(e)NB, it may be possible that the setting of the H(e)NB cell cannot appropriately follow subsequent changes in the surrounding environment. Accordingly, when the H(e)NB cell is not appropriately set, it is required to prompt re-configuration of the H(e)NB cell by supplying the configuration information to the H(e)NB from a higher-level network.
Proposed as a method to supply the configuration information to the H(e)NB is (1) transmitting from the M(e)NB by a radio channel (e.g. broadcast channel). Another method that is proposed to supply the configuration information is (2) transmitting from a higher-level network connected to the H(e)NB via an access line. The higher-level network includes a core network, an H(e)NB gateway (H(e)NB-GW), and an IP network that connects between the H(e)NB and the H(e)NB. Although the transmission path that passes through the higher-level network is typically a wired path, a radio path (wireless LAN or the like) may be used at least for a part (especially for a user's home network) of the transmission path.